hope this helps
concentrated sulfuric acid is not ionised. hence, it will not react with the metal casing of the container . dilute sulfuric acid, however, is a solution so it contains ions. it is highly corrosive as it reacts with metals of a high activity. hence, they prefer glass and plastic containers for dilute sulfuric acid, but prefer using iron drums for concentrated sulfuric acid because iron is stronger (easier to store the sulfuric acid).
in doing so, however, it must be ensured that there is no water vapour within the metal container, otherwise itll all corrode awa.